how to tell "dpkg" to NOT to download / install a broken source?

Whenever I try to use apt-get/dpkg, it tries a to install a broken source. How can I tell it to NOT do so ?

here is its error:

dpkg: error processing oracle-java7-installer (--configure):
 subprocess installed post-installation script returned error exit status 1

E: Sub-process /usr/bin/dpkg returned an error code (1)

UPDATE :

I found the perfect solution here:

https://askubuntu.com/questions/121226/how-to-completely-remove-a-oracle-jdk-that-didnt-install-properly

Solution

You need to define does this package depends on something and do you need it. If not just force to purge it with

aptitude purge oracle-java7-installer

or even

dpkg --force-all --purge oracle-java7-installer

If you need it try to determine why it is broken. Due to your posted error there is broken script in installer. So you'll need to fix it. The simplest way is to unpack it, fix script and repack. After that install should success.